How long is daytime during the following? :

1. summer solstice
2. autumnal equinox
3. winter solstice
4. vernal equinox

[ou.01]which of these is the most likely use of an electromagnetic wave which has wavelength shorter than microwaves but longer than visible light? o heat food safely o neat food safely o take images of bones and teeth o transmit radio and cellular phone signals o take images of bones and teeth o transmit radio and cellular phone signals o detect the location of objects which emit heat

The graph below plots the temperature and luminosity of stars on the main sequence.

Which barrier to economic development is shown in the following examples?